Saturday, March 19, 2011

How "Super" is the Supermoon?

I'd like to start off by saying that, once again, I think the media is dumb.  When I saw an article headline mentioning the "supermoon," I thought it was going to be an article about Superman that was either misspelled or discussing how mankind is going to need Superman if we are ever going to travel to the moon again.  Unfortunately, no, several media outlets are kicking around the term "supermoon" to describe the full moon today and asking if the "supermoon" will have a profound or adverse affect on us.  In this age of media sensationalism, nothing is too sacred or mundane to be sensationalized.  It's just a full moon - it happens roughly once every 28.5 days.  But somehow this one will be soooooooooooooooooooo special that it apparently warrants the use of the term "super" to describe it - not "above average," "slightly better," or even "great."  No, my friends, tonight you have the opportunity to witness a SUPER moon. 

 A "merely adequate" moon

What, then, will make it so super?

As many of you are aware (and many, I'm sure are not), the moon does not revolve around the Earth in a perfect circle; it actually has an elliptical orbit.  For those of you who are not familiar with the term "elliptical orbit," it means that the moon's orbit is oblong, and so the distance from the Earth to the moon varies.  The closest point is the "perigee," and the farthest point the "apogee."




the moon's elliptical orbit
 
These distance variances combined with the changing phases of the moon mean that not every full moon is of the same apparent diameter.  Obviously, they are all the same actual diameter because the diameter of the moon isn't really changing (at least, not appreciably enough for the purpose of this discussion; I don't want to hear anything about space dust or tidal forces!!!), just our perception of it due to the difference in distance.  Here's a little illustration:
Obviously, the closer the moon is, the bigger it looks

So that sets the stage for tonight's SUPERMOON!!!  The phases of the moon and the eccentricity of the moon's orbit have coincided so that the full moon tonight will be the closest full moon since March of 1993!!!  Isn't that just super???

Interesting, yes, but probably not super.  You see, just over a scant 2 years ago, in December 2008, we had an awfully close full moon too.  Don't get me wrong, this one is closer by 21 miles!  21 miles seems like a lot to me as a pedestrian, and perhaps even a passenger in a motorized vehicle, but as a planetary resident and lunar observer, 21 miles is really small potatoes.  The full moon in December 2008 occurred when the moon was 221,587 miles from the Earth.  The full moon tonight will occur at a distance of 221,566 miles - making it closer by 0.009477%.

Would Superman be quite as heroic if he was only 0.009477% more super than your average guy?

And so I say to the media, when it asks me questions such as this:

Kindly shut up.  I have a marginally-better-moon to watch!

17 comments:

  1. hahahaha I bet if no one pointed out any of this, nobody could tell the difference in size anyway.

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  2. Hahaha, I smiled at your "Would Superman be quite as heroic if he was only 0.009477% more super than your average guy?". I agree O;

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  3. Will check out the moon tonight

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  4. i hope the clouds will cooperate with me.

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  5. lol I agree, perhaps "super" is a bit too much, but it is somewhat interesting to see the moon bigger than normal.

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  6. Do you think it's the reason for all this upheaval in the middle east?

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  7. It will give me strength of 1000 men.

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  8. 'supermoon' looked like a regular sized moon last night to me. I must be doing something wrong.

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  9. I like your style of writing, nice article! I'm following!

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  10. Supermoon, be afraid... be very afraid!

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  11. It is not so super, for me makes any difrence, maybe if i be on lsd, but not. :D

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  12. When would be the best time to watch the supermoon?

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  13. Not only did the Drudge Report use the word "Supermoon" they used the headline "Dawn of the Supermoon". I think that's a great movie title about a Supermoon that saves the world, or destroys it.

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  14. saw it last night and could have sworn i have seen the money bigger at other times.

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